1. Field of the Invention
The present invention relates to an information retrieval system
2. Description of the Background Art
Hitherto, an attempt is made to improve retrieval precision and retrieval efficiency by using past operations of the user related to a search in an information retrieval system.
For example, Japanese Patent Application Laid-Open No. 8-63481 (1996) discloses a technique of changing the display order of keywords in accordance with the number of use in past search. Japanese Patent Application Laid-Open No. 8-115334 (1996) discloses a technique of changing the display order of retrieval results by keywords in accordance with the number of times of using the keyword in past retrieval. Japanese Patent Application Laid-Open No. 9-245058 (1997) discloses a technique of updating a keyword network in accordance with a keyword adoption history in past search and changing candidates of keywords to be presented to the user on the basis of the updating.
According to the techniques disclosed in the publications, although operations in the past of the user on a keyword can be reflected in a searching process and display of a search result, the intention (satisfaction level) of the user with respect to a search result is not considered. Consequently, the techniques cannot make the intention of the user with respect to a search result properly reflected in a searching process and display of a search result.